How can I select edge loops with Magic Mouse on a Mac?
Figured it out! Whoo hoo. Turns out this is what I had to do:




Select an edge (using CommandLMB)
Open the Select menu.
ControlLMB (right-click) "Edge Loops".
Select "Add Shortcut".
Press Alt Command LMB, which Blender interprets as Cmd Middle Mouse.


It seems that Alt LMB emulates the Middle Mouse Button. Not only that, mesh.loop_multi_select was the input I wanted, not mesh.loop_select, as I'd originally thought.

After I added that shortcut, this new input setting appeared in my user preferences:



All is not lost for Magic Mouse users.